Poikiloderma on the Neck: Comparing Laser Treatment Options?

I'm looking at several types of laser treatment and wondering how the machines differ? I'm seeing Fraxel, Palomar and Prolite II mentioned a lot, but not sure how these machines differ, which is newest - and if it even matters? I've tried Pulsed Dye Laser already which was effective but leaves you looking very ugly for several days and expensive. I'm trying Palomar now to even out the spots. It leaves no marks but equally, it seems pretty ineffective. Which way next?